In a continuation of studies of polyketide metabolites, work during the next year will be concentrated in three areas: 1) Development of biomimetic syntheses of tetracyclic metabolites, 2) Development of new synthetic methods of preparation of ester and amide derivatives of polyketo acids, 3) Identification of important intermediary and shunt metabolites in polyketide metabolism by methods including carrier dilution using synthetic samples of the putative intermediates.